1. Field of the Invention
The present invention relates to a network AV (Audio/Video) system that can reproduce audio sounds or video images, and more particularly, to a network AV system including a server, a client capable of connecting to the server, and an uploader capable of connecting to the server.
2. Description of the Related Art
In recent years, network AV systems using a client-server system have been provided. International Publication No. WO03/102919 and Japanese Patent Application No. 2003-290384 disclose a network AV system including a server having a database storing a plurality of pieces of music piece data and an audio client connected to the server through a LAN (Local Area Network). The audio client requests the server to provide desired music piece data and the server distributes the requested music piece data to the audio client in response. The audio client then reproduces the music piece data distributed from the server.
In the network AV system, new music piece data is registered in the server by an uploader. The uploader can have the server register music piece data. The uploader is connected to the server through the network. When music piece data is registered in the server, the uploader transmits a registration request and music piece data to be registered to the server. The server receives the registration request and registers the transmitted music piece data in a database. The uploader may be discrete or included in another device such as a server. The server registers the music piece data transmitted from the uploader and transmits the information indicating that the database has been updated (hereinafter referred to as “updating notification”) to the audio client.
The audio client receives the updating notification and obtains music piece information related to music piece data stored by the server. Herein, the music piece information refers to information to specify music piece data such as the title of the music piece and the artist and does not include the music piece data itself The audio client obtains the music piece information and requests the server to provide the desired music piece data based on the music piece information.
According to the conventional method, when a plurality of pieces of music piece data are registered in the server by the uploader, the server transmits an updating notification to the audio client every time data for one music piece is registered. More specifically, the server transmits updating notifications as many as the number of pieces of music piece data to be registered. This increases the traffic between the audio client and the server.
When the server registers a plurality of pieces of music piece data and the audio client receives a plurality of updating notifications, the audio client receives a new updating notification while it is in the process of obtaining music piece information in response to another updating notification. In this case, the audio client must stop obtaining the music piece information and must obtain the music piece information all over again. This also gives rise to increase in the traffic.